Road shoulders may be formed from a granular material such as gravel or stone. The granular material is deposited adjacent an edge of a road. The granular material is generally compacted prior to use to support the weight of a vehicle. Such road shoulders are typically known as soft shoulders. Failure to compact the granular material prior to use of the soft shoulder may result in excess erosion or displacement of the granular material.
An asphalt roller or a tire of a vehicle may be used to compact the granular material forming the soft shoulder. The asphalt roller or the vehicle traverses a width of the soft shoulder, a weight of the asphalt roller or the vehicle compacts the granular material.
To facilitate water removal from the road and transition the road surface to adjacent ground, the soft shoulder typically includes a grade. The grade of the soft shoulder may be particularly steep when the soft shoulder is formed adjacent a ditch or other drop in elevation. The asphalt roller or the vehicle used to compact the soft shoulder may slide off the soft shoulder and roll over as the asphalt roller or the vehicle traverses the width of the soft shoulder. Generally, the asphalt roller cannot adjust to the grade of the soft shoulder without leaving a driving surface of the road. Further, the tire of the vehicle may leave a rut in the soft shoulder. Water collecting in the rut hastens erosion of the soft shoulder.
Specialized equipment is available for the compaction of the soft shoulder. U.S. Pat. No. 6,612,774 to Dulin discloses an apparatus for compacting road shoulders. Dulin discloses the apparatus for compacting road shoulders including a roller having a fixed grade. Dulin further discloses the apparatus for compacting road shoulders extending beyond a normal width of the vehicle to which the apparatus for compacting road shoulders is attached. The apparatus for compacting road shoulders extending beyond a normal width of the vehicle may restrict mobility of the vehicle and may lead to an accidental collision with another vehicle or a stationary object.
U.S. Pat. No. 5,304,013 to Parsons also discloses a road shoulder compacting apparatus extending beyond a normal width of the vehicle the road shoulder compacting apparatus is attached to. Parsons further discloses the road shoulder compacting apparatus including a roller mounted on a fixed arm. The road shoulder compacting apparatus including a fixed arm may limit the accessibility of a vehicle to which the road shoulder compacting apparatus is attached. Further, the road shoulder compacting apparatus may increase a likelihood of a rollover accident when used to compact shoulders having a steep grade, as the vehicle must operate closer to the road shoulder.
It would be desirable to have an apparatus for compacting road shoulders able to be positioned within a normal width of a vehicle when not in use, able to vibrationally compact the road shoulder, and having a compacting attachment that may be adjusted according to a grade of the shoulder.